添加 github.com/pion/dtls 代码

dtls-2.0.9/flighthandler.go

@@ -0,0 +1,57 @@
+package dtls
+
+import (
+	"context"
+
+	"github.com/pion/dtls/v2/pkg/protocol/alert"
+)
+
+// Parse received handshakes and return next flightVal
+type flightParser func(context.Context, flightConn, *State, *handshakeCache, *handshakeConfig) (flightVal, *alert.Alert, error)
+
+// Generate flights
+type flightGenerator func(flightConn, *State, *handshakeCache, *handshakeConfig) ([]*packet, *alert.Alert, error)
+
+func (f flightVal) getFlightParser() (flightParser, error) {
+	switch f {
+	case flight0:
+		return flight0Parse, nil
+	case flight1:
+		return flight1Parse, nil
+	case flight2:
+		return flight2Parse, nil
+	case flight3:
+		return flight3Parse, nil
+	case flight4:
+		return flight4Parse, nil
+	case flight5:
+		return flight5Parse, nil
+	case flight6:
+		return flight6Parse, nil
+	default:
+		return nil, errInvalidFlight
+	}
+}
+
+func (f flightVal) getFlightGenerator() (gen flightGenerator, retransmit bool, err error) {
+	switch f {
+	case flight0:
+		return flight0Generate, true, nil
+	case flight1:
+		return flight1Generate, true, nil
+	case flight2:
+		// https://tools.ietf.org/html/rfc6347#section-3.2.1
+		// HelloVerifyRequests must not be retransmitted.
+		return flight2Generate, false, nil
+	case flight3:
+		return flight3Generate, true, nil
+	case flight4:
+		return flight4Generate, true, nil
+	case flight5:
+		return flight5Generate, true, nil
+	case flight6:
+		return flight6Generate, true, nil
+	default:
+		return nil, false, errInvalidFlight
+	}
+}